Deploy an matlab file to executable - matlab

Question

I want to deploy an m file into an executable. I am using mcc command: mcc -m epidemic.m. Epidemic is my function which takes no arguments and returns a vector and write that vector to txt. Mcc creates epidemic.exe and when I am running that exe it creates the txt file however it seems that it doesnt return values (the return value of .exe). I am trying to run the exe from matlab using:
cmd = ['epidemic.exe '];
system(cmd);
It return cmdout " and status 0. How can I take the returned values of the .exe?

Answer 1

When you compile matlab code like:
function [out1, out2] = epidemic(in1, in2, in3)
%[
...
%]
to standalone (mcc -m epidemeic.m), Matlab produces somehow the following pseudo c-code and compiles it to .exe:
int main(int argc, char** argv)
{
// Load compiled code produced by mcc
HMCRInstance* hInst = loadByteCodeProducedByMccFromResources();
// Similar to have wrote in matlab "epidemic(argv[0], argv[1], ...)"
// 1) Without asking for any argument output
// 2) Argument inputs are passed as strings
int errorCode = mclFevalFromExeArg(hInst, "epidemic", argc, argv);
return errorCode; // only indicates if call to 'mclFEvalFromExeArg'
// succeded, it does not relate to out1, out2 at all.
}
NB: If you want to see the exact code produced by mcc, use mcc -W main -T codegen epidemic.m
So, directly compiling to standalone, you cannot work with outputs of your Matlab function. If you need to play around with output arguments of epidemic, either
[Simple solution] Consider saving outputs to files or display them to shell console using disp (NB: you can use isdeployed in your .m file to check if you're running from matlab or from compiled code).
[Advanced solution] Consider compiling your code to shared library (mcc -l epidemic.m) instead of standalone (mcc -m epidemeic.m)
NB: When you compile your code to shared library, mcc will produce a dll that exports the following function:
extern LIB_epidemeic_C_API
bool MW_CALL_CONV mlxEpidemic(int nlhs, mxArray *plhs[], int nrhs, mxArray *prhs[]);
nrhs/prhs are the number of input arguments and their values (as mxArray type). And nlhs/plhs are the ouput arguments you want to have when calling epidemic. Up to you to do the marshaling between mxArray and equivalent C native type.
EDIT
As you indicate that epidemic returns a vector of values, you can display them from standalone like this:
function [output] = epidemic(v1, v2, v3)
%[
% When called from system cmd line, v1, v2, v3 are passed
% as string. Here is how to convert them to expected type if required
if (ischar(v1)), v1 = str2double(v1); end
if (ischar(v2), v2 = str2double(v2); end
if (ischar(v3)), v3 = str2double(v3); end
...
output = ...;
...
if (isdeployed())
disp(output);
end
%]

Answer 2

An exe does not have a return value, you need to find another way to transport the data back, for example via console outputs or text files. What you get is the error code and error message.